'Cretaceous Kraken' Ruled Ancient Oceans Alongside Dinosaurs, New Fossil Reveals
Long before sailors told stories of the kraken — a mythical sea monster said to drag ships beneath the waves — something eerily similar may have actually existed.
Only this version was real.
A newly identified finned octopus from the Cretaceous period, known from a rare giant octopus fossil, stretched up to 62 feet long and may have ruled ancient oceans as a top predator.
The findings were published Thursday, April 23 in the journal Science.
A Real-Life Kraken of the Cretaceous Seas
The newly described new species, Nanaimoteuthis haggarti, lived between about 86 and 72 million years ago — at the same time dinosaurs like Tyrannosaurus rex, Triceratops and Velociraptor roamed the land.
At full size, it could reach lengths between 22 and 62 feet, making it significantly larger than today’s giant squid, which tops out around 39 feet.
“These animals were remarkable… they represent what could be described as a real ‘Cretaceous Kraken,’” lead researcher Yasuhiro Iba told Reuters.
A second species, Nanaimoteuthis jeletzkyi, was smaller — but still massive — measuring up to 25 feet long. Together, they rank among the largest invertebrates ever documented.
Not a Myth — but Close Enough to One
The kraken of legend comes from Norse folklore, where it was described as a massive tentacled creature capable of sinking ships.
While this Cretaceous kraken didn’t terrorize sailors, it likely played a similarly dominant role in its environment.
These octopuses shared the oceans with giant marine reptiles like mosasaurs and plesiosaurs — some reaching up to 50 feet long — as well as sharks comparable to modern great whites.
And they weren’t just swimming alongside them. They were likely competing with them.
Built Differently From Modern Octopuses
Unlike most octopuses today, these ancient giants were finned octopuses, using paddle-shaped fins on their heads to move through the water. That places them among the earliest known examples of this body type in the fossil record.
Fossil evidence for the species comes from Japan and Vancouver Island in Canada — and finding it at all was unexpected.
“We were surprised. The fossil record of octopuses is extremely limited, so finding animals this large… was beyond our expectations,” Iba told CNN.
That’s because octopuses are notoriously difficult to fossilize because their bodies are almost entirely soft tissue.
The only part that reliably survives is the beak — a hard, chitin-based structure similar to what’s found in crab and insect shells.
Researchers reexamined 15 previously discovered jaw fossils and identified 12 more embedded in rock. Using 3D imaging and AI-assisted reconstruction — a method Iba calls “digital fossil mining” — they were able to estimate the size and structure of these animals.
An Apex Predator That Crushed Its Prey
Those fossilized jaws reveal how these creatures lived — and hunted. They show extreme wear, consistent with repeatedly crushing hard prey like shells and even bone.
“In the largest specimens, about 10% of the total jaw length appears to have been lost due to wear,” Iba said. “This is more severe than what is typically seen in modern octopuses… that feed on hard prey.”
Their diet likely included large fish, shelled cephalopods and clams.
And like modern octopuses, they wouldn’t have relied on jaws alone — using their flexible arms to capture prey before breaking it down.
The evidence suggests these weren’t just large animals. They were sophisticated hunters.
Uneven wear on the fossilized beaks points to lateralized behavior — similar to handedness in humans — indicating a level of behavioral complexity.
Iba noted that, like modern octopuses, they likely relied on intelligence as much as physical power when hunting.
This Giant Octopus Has Scientists Rethinking Ancient Oceans
For roughly 370 million years, scientists believed marine ecosystems were dominated by vertebrate predators — fish, sharks, marine reptiles and eventually whales.
This discovery changes that narrative.
“Their existence changes how we view ancient oceans,” Iba said. “Instead of ecosystems dominated solely by vertebrate predators, we now see that giant invertebrates such as octopuses also occupied the very top of the food web.”
In other words, the oceans may have had their own version of a kraken all along.
What Else Is Still Out There?
Researchers plan to expand their “digital fossil mining” technique to uncover more hidden species — especially those made of soft tissue that rarely fossilize.
“Our goal is to reveal the hidden players of ancient ecosystems and build a much more complete picture of how past ecosystems really worked,” Iba told CNN.
If a 62-foot finned octopus has been hiding in the fossil record this whole time, it raises a bigger question: What other “krakens” are still waiting to be discovered?
This article was created by content specialists using various tools, including AI.
